This invention relates to an electric powered hand mixer for processing food materials, with switching arrangements adjustably disposed on a housing and featuring different settings for activation of a continuous on mode and a pulse mode, with tool mounts for holding various tools including, for example, a mixing or kneading tool or a purxc3xa9eing wand.
A hand mixer of this type is known from European patent specification 0 529 266 B1. On the electric powered hand mixer described therein electric switching devices ensure that either a continuous-on mode or a pulse mode is set automatically according to the choice of processing tools. The hand mixer is provided with identical tool mounts for a kneading or mixing tool, and with a further tool mount for a purxc3xa9eing wand featuring a cutter blade.
The first electric switching device is a main switch which is adjustable to several continuous-on settings featuring different speeds from I to III on the one hand and also into a pulse setting IL on the other hand. Whereas all the operating settings are possible when kneading or mixing tools are inserted in the hand mixer, if a purxc3xa9eing wand is inserted in the corresponding tool mountxe2x80x94the latter being positioned at a location away from the tool mount for the kneading or mixing toolsxe2x80x94the main switch may indeed be moved to the various speed settings but the drive motor can only be switched in the pulse setting; this is owed in particular to a second electric switching device which, when the purxc3xa9eing wand is inserted, electrically blocks the main switch in its continuous-on settings in order to prevent the cutter blade causing injury in the event of incorrect handling.
On a hand mixer known from DE 79 02 965 U1 it is possible, using a switching device positioned directly adjacent to a release member and with a switching member arranged in a direction transverse thereto, for all three devices to be operatively associated with each other by corresponding stops and abutments. In a first rotary position of the release member this operative relationship can block the release member itself in its axial adjustment and at the same time permit the adjustment of the switching member. In a second rotary position of the release member the latter then permits its axial adjustment, disabling at the same time the adjustment of the switching member. As a result of the special construction of the switching member and the release member it is thus possible with the described hand mixer for either only the switching member to be adjusted in order to switch on the hand mixer or for only the adjustment of the release member to be enabled, causing, upon its actuation, ejection of the kneading or mixing tools in axial direction. The release member is constructed as a slotted sleeve so that in its one rotary position (switch-on position) the switching member is engageable within the slot in order to move the sleeve and in its 90xc2x0 rotated position (eject position) movement of the switching member is inhibited.
For this hand mixer to be used as a chopper it is also provided with a pulse setting M which enables the appliance to be switched on only for as long as the user keeps the switching member pressed. This requires the release member to be moved first into a rotary position where on the one hand a further inhibiting member is moved into operative association with the switching member, thus preventing the continuous-operation settings I to III from being switched on. On the other hand it is not possible either for the cutter blade to be ejected because, in the pulse setting M, the switching member engages within the slot of the release member, preventing the release member from being displaced in axial direction.
It is an object of the present invention to provide an electric powered hand mixer of the type initially referred to which, by simple and economical means, enables either a continuous-on mode or a pulse mode to be set and to control these operating modes according to whether mixing and kneading tools or a cutter blade (purxc3xa9eing wand) are inserted in the appliance.
This object is accomplished by a hand mixer of the present invention, on which the continuous-on mode and the pulse mode can be set independently of each other at different switching devices. These two switching devices are mutually interlocked by mechanical means. To accomplish this, the two switching devices and the lock release element are coupled together for the purpose of providing an interlock. On the one hand this represents a particularly reliable and secure interlocking of the continuous-on mode and the pulse mode, on the other hand it can be manufactured in a particularly simple and hence economical manner.
As a result of the invention""s exclusively mechanical linkage between the lock release element and the first and second switching device it is possible for the switching function for the continuous-on mode of the mixing or kneading tool and the switching function for the pulse mode of the purxc3xa9eing wand to be performed separately from the first and second switching device. The first switching device can only be actuated to activate the continuous-on mode when a mixing or kneading tool is inserted and the lock release element is thus in its upper position. Actuation of the second switching device is then prevented at the same time. The second switching device can only be actuated to activate the pulse mode when no kneading or mixing tool is inserted in the corresponding tool mount, actuation of the first switching device to activate the continuous-on mode being blocked simultaneously. And finally, the lock release element cannot be actuated to eject an inserted mixing or kneading tool when the continuous-on mode is activated.
The interlocking members for establishing the mutual operative relationships comprise simple projections and corresponding bores or recesses on or in the lock release element, the first switching device and the second switching device.
As a result of other features of the invention, the lock release element is axially displaceable in its longitudinal direction, with the displacement in upward direction being performed by inserting the mixing or kneading tools. Displacement of the lock release element in downward direction is initiated during ejection of the mixing or kneading tools by pressing down onto the release button of the lock release element. When mixing or kneading tools are in inserted position, the interlocking members of the lock release element and the switching device are in relative alignment so that the switching device can be moved to its operating settings. Ejection of the mixing or kneading tools is impossible in this setting. When mixing or kneading tools are in ejected position, the lock release element is so far from the interlocking member of the switching device that, during movement of the switching device, the former inhibits movement of the latter, making it impossible to switch on. In this position it is only possible to actuate the pulse switching device, which is aligned in turn with an interlocking member of the switching element.
As a result of other features of the invention, it is possible for the first switching device to be displaced in longitudinal direction of the hand mixer housing surface in what amounts to a particularly simple mode of operation.
Another feature of the invention enables the first switching device to be displaced in longitudinal direction of the hand mixer surface and the second switching device to be displaced simultaneously in vertical direction to said surface. These two orthogonal directions of movement of the two switching devices enable easy operation without any need to provide the user with special explanations for moving the switching devices.
Another feature of the invention results in a particularly simple, easy to manufacture mechanical construction of the interlocking device. At this point it should be noted that, in the interest of simplicity, the two electric switches for actuating the two switching devices are not shown in the drawing because they are not visible in this plane. Nor are the guides of the switching devices in the housing shown in any detail. The same applies for the motor, gearing, cables and other internal parts of a hand mixer.
Other features of the invention result in particularly simple embodiments of the second switching device without any need for elaborate components.
Further features, application possibilities and advantages of the present invention will become apparent from the subsequent description of embodiments of the invention illustrated in the Figures of the accompanying drawings. It will be understood that any single feature and any combination of single features described or represented by illustration form the subject-matter of this invention, irrespective of how they are summarized in the patent claims or their back references and irrespective of their wording and representation in the description and drawings, respectively.